1. Field of the Invention
The present invention relates to childproof container closures for packaging liquids, powders, pills, and the like and, more particularly, to a childproof container closure in which a cap must be deliberately acted upon through the use of forces or movements greater or more complex than that of which a child is capable of accomplishing in order to permit the cap to be moved to a container-open position.
2. Description of the Prior Art
Numerous versions of childproof container closures are known, the object of all of which is to prevent a child from having access to the container contents. Generally speaking, these prior container closures require a deliberate manipulation of the closure in order to have access to the container contents. For example, typical container closures require that a cap be distorted or acted upon by force applied in some pre-determined manner or direction in order to release a locking device, and removal of the cap thereafter is permitted upon the application of force in a different direction.
One known class of container closures requires that an outer portion of the cap be squeezed in order to flex the outer portion and thereby disengage interlocking, concealed components. Thereafter, provided the cap is continued to be squeezed for at least a certain period of time, the cap can be rotated with respect to the container and unscrewed from a threaded dispensing end of the container. In another class of container closures, the cap includes an inner, cylindrical skirt and an outer, cylindrical skirt. The inner and outer skirts are connected to each other. By squeezing the outer skirt at indicated locations, the inner skirt is distorted and interlocking components carried by the inner skirt and a portion of the container are disengaged, thereby permitting removal of the cap. In yet another version of childproof closures, a cap must be rotated to a particular radial location with respect to the container. Provided the cap is kept at the predetermined radial location, axial movement of the cap with respect to the container will be permitted; this will be due either to the disengagement of interlocking components at the predetermined radial location, or because access to cap-gripping members will be provided at the predetermined radial location.
Although the prior container closures referred to are believed to adequately protect the container contents against access by a child, certain concerns exist above and beyond the achievement of their basic objective. One of the important concerns relates to the expense of manufacturing the cap. Generally speaking, it is moe difficult and expensive to manufacture container closures having threaded surfaces than it is to manufacture container closures without threaded surfaces. Many of the prior devices include threaded surfaces, and this feature means that the expense of the cap tends to be higher than desired. Yet other container closures sometimes are too difficult to use conveniently. That is, due to the actuating forces required or due to the required manipulation of small, difficult-to-grasp elements, even some adults have difficulty in moving the cap to a container-dispensing position. A related concept is that of "feel," or quality of cap movement. Childproof caps, if possible, should snap into a container-closing position, and should either snap to a container-open position or should move with a certain amount of drag to a container-open position. If the foregoing type of cap action is provided, the user will know when the container is closed or open merely by the feel and sound of the cap as it moves with respect to the container. Certain prior container closures have been deficient in the quality of cap movement.